Registered

I've got a 69 GTO which has a TH400, but when I try to shift into reverse it goes into neutral. The other gears are messed up too. Neutral is drive, drive and low gear work as drive too. Park puts it in park. Does anyone have a diagnosis on this problem?

Super Moderator

I've got a 69 GTO which has a TH400, but when I try to shift into reverse it goes into neutral. The other gears are messed up too. Neutral is drive, drive and low gear work as drive too. Park puts it in park. Does anyone have a diagnosis on this problem?

You may have a few different scenarios going on. Your back lock linkage may be out of adjustment. Your shift cable may be helping cause this too or in combination with the back lock linkage. Take a look at the shift cable. It should not be stretched taunt, check the cable as it is attached to the bracket. Look to see if the sheath is still crimped, it may be torn away from the crimped part and as the gears are shifted the cable could be binding there preventing the gear shift from proper placement. The cable though if there is an issue there will give you resistance in the shifter when you go to engage it. Your issue IMO is with your back lock linkage adjustment. If your back lock linkage is out of whack it will mess up your alignments. Take your hands and wrap them around your steering column and try and turn it. My guess is you will be able to and you shouldn't. If you can, your back lock linkage needs adjusted. Pictures of that area would help.

Registered

I have a similar issue as this except every gear position is forward. I am guessing it is an adjustment but looking for input. I adjusted the shift cable because i did not have park, all other gears were good, i now have park but only forward gears. 1968 GTO TH400

Guys, I'm a novice and trying to find out what diff I have in my GTO. It is a ten bolt.
I can only find numbers on the rear of the diff. I can't see any numbers on the axle tubes or tags on the brake backing plates.
The digits on the diff are...
K188
9795082
(I think) photo attached.
Thanks
Jim

Hello all. I jumped in my 66 Tempest last night, took it for a drive and found that it wouldn't shift out of 1st gear. It's a 2 speed automatic transmission. The previous owner put a 455 from a 1970 Grand Ville in it but i'm not sure what type of trans it is. Is it a Powerglide? Anyway, it...

I have a 69 GTO with a 8.2 Limited Slip and I have a 8.5 Limited Slip from a 1985 Olds 442 with 3.73 gears and the 200 R4 overdrive trans as well.
Has anyone put a 80's 8.5 in their older Pontiac.
It looks like the overall width dimension on the 8.5 are 3" shorter and the shock holes are 2"...

66 GTO Super Turbine 300 2 speed trans is leaking from passenger side. I have already replace the pan gasket and still has the same leak coming from the passenger side. What could be causing this??? Thank you for any information is advance!!!!

Hi, hoping someone can help me. I have a 71 GTO convertible which I have had for 20 years. About 15 years ago I purchased a THM 400 automatic transmission with a switch-pitch stall designed for high performance. At the time I intended to drag race the car but never did. It is just a...